Pressure controlled throttle valve



May 7, 1935. W. A HENRY 2,000,387

PRESSURE CONTROLLED THROTTLE VALVE Filed June 25. 1954 Ng E y: m Ilmgmc/wim MHz/m14, Henry Patented May 7, 1935 UNITED `STATES PATENT OFFICEPRESSURE ooNraoLLED rHRor'rLE William A. Henry, Littleton, coro.

Application June 25, 1934,. Serial No. v732,269

7- claims. .(cl. zas-2e) l This inventionl relates to improvements inpressure controlled throttlevalves.

In the operation of steam generating plantsv of the type employingforced.r draft, it is. desiralrble to control the speed of the fan whichis used forY controlling the draft, in accordance with the Steam.pressure within the boiler so that whenther pressure. within the boileris low Yor .decreasing the speed of the `fan will be high,.therebylofproducing suiiicient draft tol secure maximum combustion andsimilarly when the pressure has attained the maximum Value,. thespeed ofthe fan must `be reduced so as tov retard the combustion., but. in nocase must ythe fan be stopped lsyentirely. f- .1

It isthe object of this invention to lproduce a throttlevalvethat can beintroduced in thesteaxn supply pipe running from the boiler to a steam'turbine ofthe type employed for operating a fan i in connection with aforced draft system.vr The, throttle valve is so constructed thatthearnount of steam. that .is ypermitted to flow will be variedinversely in accordance withv thepressure in the steam boiler.

Figi. 1 is a side elevation of lmy improved vsteam controlled throttleValve., parts being broken;A

away so as to better disclose the construction;

2 is a section taken on line 2-2, Fig. 1,

and-shows the position of the parts when the; i Y

28.and issurrounded by means of a helical spring valve occupies itsmaximum open position;

Fig. 3l is aside elevation partly in section showing the position of theparts when the valvey is y Fig. 4 is a diagrammatic representationshowing the valve in the position it occupies between the` boiler andthe steam turbine. A

In the drawing reference numeral 5 designates a steam boiler andreference numeral 8- a steam turbine which is connected by means. of ashaft I to a suitable fan which has been designated by referenceVnumeral 8. The turbine is: connected'v 55. been vshown in Figs. 1, 2 and3 from which it will The Vabove and other objects.A that may becomebeseen matin. eopsists of e, body member H that has a cylindrical openingzI2 extendingdnwardly fronrone end thereof. The upper end ofthe bodymember: is closed by an end wall I3 which is provided withy a threadedopening I4 into which one end` of4 the pipe 91 extends in the mannerShown.` Surrounding the lower end of memberV II is a flange l5 that isprovided with two threaded openings I6. A plate l1- of the same outsidevdiameter as the flange I5 is located beneathV the latter and is held in.place by means y of. the rods i8 and the nuts lil.y The plate vI'l hasan opening 2|).A .thatssomewhat smallerin diameter than thecylindricalopening I2 and therefore. the platev extendsinwardly beyondthe wall ofthe cylindrical opening inthe manner shown.most. clearlyirxfliiig.` 2. Located within the cylindricalA opening isa. piston 2l.This piston hasacentraleavity 225 that. extends from its upper end to apoint near the lower end in, amanner shown. in Fig. A2. An elongatedport 23v-extends7 through the Wall of thepiston and communicates. Ywiththe corresponding port 24 inthe wall, of the cylinder; The piston isprovided'with. two or more piston ring grooves 25 near each end andlocated in these grooves are ordinary piston rings. The bottom of thepistonA is provided with a threaded opening. 26 into which` the. upperend, of thel rod k21 isthreaded in the manner indicated in Fig.. 2. Therods or bolts I8` extend downwardly for aj considerable distance and?are lconnected near their lower ends by means of aplate `28 which isheld in adjusted position by means of twopairs of nuts 29. By adjustingthe nuts, 29 the vplater 28 can be moved towards or away from the platev20. The piston rod. 21 extends. through .an opening in thefplate 30.'Illeupper. end of this spring abuts the lower endy of the piston, whilethe lower end rests on the. upper 'surface oiplate 28. The spring 340V,is alwayslundercompression, and. tends to move the pistonY upwardlytowards the top of the cylindricalopening and when there is no pressureacting on the. piston, the latter will have.. its upper end in contactWith'the inner surface of the end wall I3. The Spring is yofsuch'strength that when the pressure in the. boiler attains the maximumvalue, it will move.V the piston down-` wardly tothe position shown inFig. 3 in which position'. the/ports' 23 and- 24 are 'broughtv out ofalignment so `that. very-.little .steam will pass tl'irougli.` .thepipes. 9. and..A to. the turbine. The parts, are,v so'adjusted,thowever,l that suiiicient steamiwill always nowto cause the turbinetoopening of the throttle valve.

turbine and increaser the speed of the latter,v

whereby the draft will be increased and in this way the speed of the fanwill be maintained at the proper value to securethe generation of thenecessary amount of steam to maintain the pressure at the desired value.The pressure ,tobev maintained within the boiler can be adjusted byadjusting the tension of the 'spring'30,' which can be done by movingthe nuts 29 in the manner,

suggested. It will be observed that the piston is provided with two ormore rings near each end and that the port 23 extends through the wallof `the piston between the rings.- The surface of the piston between thetwo innermost rings isl spaced a short distance from the surface-of thecylinder so as to permit a small amount of steam to ow between the wallof the piston and the wall of the cylinder, thereby producing a balancedeffect. Since it is not intended to cut oi the steam entirely from theturbine at-any time, slight leakage 'dueto the clearance between thepistonA and-the cylinder -can'do no harm and therefore such clearance isprovided so as to produce the balanced effect mentioned.

Attention is called to the fact that in this valve the piston performstwo; separate `functions and serves both as a valve member to controlthe iiow of the steamto the turbine and also` as la pressure measuringdevice' which determines the The piston rod v2l is provided with a`longitudinally extending 'groove 2i. A spline coop-'- erates with thegroove forfthe purpose of preventing the pistonand the Vpiston rod fromturn-V ing in the cylinder and thus assures that the ports 23 and 24will always be properlypositioned so as to fully register with eachotherwhen the pistonmovesjin the cylinder. l Y

From the above description it willbe seen that the pressure controlledvalve that forms the subject of this invention is of a very simple andsubstantial construction and that it; can be readily inserted in thesteam'line between a boiler and a steam turbine or other steam engine soas to control theflow of'fsteam in accordance with the pressure intheboiler.' j

In the embodiment illustrated, the" area of the opening through 'thevalvel varies inversely with the steam pressure as this is necessaryin'order to obtain the results desired. Although the valve has beendescribed in connection `with ya forced draft steam generating plant,itl can, of course, be employed in any place where the flow of iiuidthrough a pipe is to be controlled in accordance with some variablepressure source.

Having described the invention what is claimed asnewis: Y 'r l. Apressure controlled throttle valve, comprising, in combination, a bodymember having a cylindrical opening, one endof the opening being closed,a. piston mounted for reciprocation in the opening and resilientmeanscomprising a spring for urging the piston towards the closed endof theycylindrical opening, the space between the piston and the closed 'endof the cylindrical opening forming a pressure chamber, the piston havingan opening extending thereinto from the pressure chamber, and an openingextending through the wall of the piston and forming a port, the wall ofthe body member having a discharge port so located that it will bebrought into register with the port in the piston at one position of itstravel.

2. A pressure controlled throttle valve, comprising, in combination, abody member having a cylindrical opening, one end of the opening beingclosed, a piston mounted for reciprocation in the opening, resilientmeans comprising a spring for urging the piston towards the closed endof the cylindrical opening, the space between the piston and the closedend of the cylindrical position of its travel, and'means for holdingthepiston vfrom turning.

3. A pressure controlled throttle valve, comprising, in combination, abodymember having a cylindrical opening, one end of the opening beingclosed, a piston mounted for reciprocation in the opening, resilientmeans comprising a spring for urging the piston towards the closed endof the cylindrical opening, the spacev between the piston and the closedend of the cylindrical opening forming a pressure chamber, the pistonhaving an opening extending thereinto from the pressure chamber, and anopening extending through the wall of the piston and forming a port, thewall ofthe body member having a discharge port so located that it willbe brought into lregister with the port in the piston at one position ofits travel, means for holding the piston `from turning, and means foradjusting the j tension ofthe spring. -f l 4. A pressure controlledthrottle valve,l comprising, in combination, a body member having acylindrical opening, one end of the vopening being closed, a pistonmounted for reciprocation in the opening, resilient means comprising aspring for urging the piston towards the closedend of the cylindricalopening, the space between the piston andthe closedend of thecylindrical opening forming a pressure chamber, the piston having anopening extending thereinto from the pressure chamber and an openingextending through thelwall of the piston and forming a port, the wall ofthe body member having a discharge port so located that it will bebrought into register with the port in the piston at one position of itstravel, and means for radjusting the tension of the' spring.

5. A pressure controlled valve of the type described, comprising, incombination, a body member having a cylindrical opening extendinginwardly from one end thereof, a piston slidably mounted in thecylindrical opening, the space between the end of the piston and thewall of the closed end of the opening forming a pressure chamber, apiston rod secured to one end of the piston, a guide for the piston rod,means for attaching the guide to the body member, a compression springextending between the guide and. the vouter end of the piston for urgingit towards the closed end'of the cylindrical opening, the body memberhaving a discharge port extending through its wall, the piston having anaofi opening extending from the end that is located in the cylindricalopening to the outside of the piston at a point between its ends, theopening in the piston wall being positioned to register with thedischarge port in the body member at one point in the piston travel.

6. A pressure controlled valve oi the type described, comprising, incombination, a body member having a cylindrical opening extendinginwardly from one end thereof, a piston slidably mounted in thecylindrical opening, the space between the end of the piston and theWall of the closed end of the opening forming a pressure chamber, apiston rod secured to one end of the piston, a guide for the piston rod,means for attaching the guide to the body member, a compression springextending between the guide and the outer end of the piston for urgingit towards the closed end of the cylindrical opening, the body memberhaving a discharge port extending through its wall, thekpiston having anopening extending from the end that is located in the cylindricalopening to the outside of the piston at a point between its ends, theopening in the piston wall* being positioned to register with thedischarge port in the body member at one point in the piston travel, theopening in the wall of the piston being moved out of communication withthe discharge port in the body member when the pressure in the pressurechamber exceeds a predetermined value.

7. A device in accordance with claim 1 in which there is a means foradjusting the force exerted on the piston by the spring.

WILLIAM A. HENRY.

